Perkin Elmer file reader

[borondics]

Based on existing code from specio and from colleagues at the Diamond synchrotron comes a new reader for Perkin Elmer files.

[stuart-cls]

Great!

You need to add the test files to MANIFEST.in before we can find out if the tests pass :)

Generally, I don't love the structure of the reader:

1. It's two readers jammed into one for no reason I can see.
2. I don't really like the API boundary between the specio code and the reader code. Looking at specio, I can see why it was done this way. I would prefer to keep the code-copies in the utils folder and the Orange-specific stuff only in the reader section.

I understand if you don't have much appetite for pedantic refactoring :) I don't think it will affect maintainability so skip it if you'd rather not.

[borondics]

Thanks for the comments guys, I tried to improve things! Have a look...

[markotoplak]

Before merging, this should be rebased into a single commit. Also, there is a file with CRLF (main lint's complain). This should be reformatted.

I can do this steps, when ready.

[stuart-cls]

This is good from my side, don't forget @markotoplak comment about line endings and squashing the commits.

[borondics]

Then, it is good for me too... @markotoplak, would you merge it?

[markotoplak]

Tests are bad. Test should not skip complex parts of the code, like image coordinates, which are not tested at all. This should be improved.

[markotoplak]

I am merging this as is, but tests should really be made better.

[borondics]

Thanks for merging! I added map coordinate tests in #776